The curves to the right were devised to show the effects of Energy Factor on power consumption and energy costs.
They apply to a typical California pool containing 25,000 gallons and costing $0.25 per kilowatt hour to operate. Results will vary for regions with different use conditions and energy rates.
The top chart covers energy use in kilowatt hours, while the lower addresses cost in dollars spent per year.
To achieve Energy Star status, a pump must show an Energy Factor of 3.8 or higher, designated on these curves by the blue star. Some pumps have reportedly been tested to show an Energy Factor of more than 10.
The more drastic energy savings can be seen at Energy Factors under 10, after which use and costs taper down more gradually.
The pool and spa industry has just seen the launch of an Energy Star designation specifically designed for its products.
In February, the Environmental Protection Agency began the program for inground residential pool pumps. Advocates of green products hope that consumers’ familiarity with the Energy Star logo will make more homeowners comfortable with the extra costs associated with energy-efficient pumps.
“About 80 percent of the U.S. population recognizes Energy Star for what it is,” says Christopher Kent, product manager for Energy Star pool pumps. “A large percentage of those consumers use it as a market differentiation to determine what they’re going to purchase.”
Here, experts discuss the new program and the prospects of seeing the logo become available for other product categories.
Not all products are considered for Energy Star programs.
The Environmental Protection Agency, which develops and implements the programs, has a set of guidelines that it uses to determine what kinds of products can qualify for Energy Star. For starters, the designation is reserved for items that consumers will purchase in their entirety, as opposed to component parts. Additionally, the programs are geared toward products that have enough manufacturers producing them so that it doesn’t favor any one company’s proprietary technology. In this regard, pool and spa pumps are unique in that they have one of the lowest number of producers to quality for Energy Star.
It was utility companies who had originally approached the EPA several years ago with the idea of starting a program for energy-efficient pumps. They had hoped to use such a program to guide their own rebate plans. The agency took a while to bite, but when it did, it bit hard.
“Based on our workload ... we put it off for a few years, and then we finally got around to looking at the opportunity and the potential savings. And we jumped at it, just because there were huge energy-saving opportunities,” Kent says.
The EPA decided to focus its pool pump program on inground residential units. It based the requirements on an already-existing document — California’s appliance-efficiency standard, Title 20. Among other things, that state code says that newly purchased pumps cannot be single-speed, unless they’re under 1 horsepower. Anything above must be two-, multi- or variable-speed. But the EPA needed to avoid language that promoted specific technologies, so rather than excluding single-speed units, it focused on performance in developing the Energy Star parameters.
To qualify for the label, pumps must be tested and certified to reach an energy factor of 3.8 or higher. Energy factor is defined as gallons pumped per watt hour.
“It’s a metric that captures both the motor and wet-end efficiency,” says Erica Porras, associate consultant with ICF International, a Washington, D.C.-based contractor that supports the EPA in its Energy Star program. “Whereas other metrics only capture one or the other, this combines both. It’s an easy way for consumers to know how much energy is being used for the amount of work [the pump is] doing for them.”
For a product to qualify, it has to rank among the 25 percent most efficient on the market. To arrive at the target energy-factor, the EPA took pump-efficiency data largely collected for California’s Title 20 and selected the number that separated the top 25 percent most efficient. As it happens, virtually all the pumps meeting that standard were two-speed, multi-speed and variable-speed, while the vast majority of single-speed models fell below the line. There were one or two single-speed models that attained the required energy factor, but they were very small and wouldn’t be suitable for most inground pools, says Gary Fernstrom, principle engineer with Pinnacle Land and Energy Services in Denver, who was instrumental in developing California’s Title 20 and the Energy Star program.
The EPA estimates that Energy Star-rated pumps are 30 to 72 percent more energy-efficient than standard models, saving consumers an average of $160 per year.
“That is actually a very conservative estimate,” Kent says. “If all the pool pumps sold in America were Energy Star qualified, that would be a savings of $113 million per year, which is equivalent to the greenhouse-gas emissions of 140,000 vehicles. And that is a very conservative calculation.”
So far, Pentair Aquatic Systems, Hayward Pool Products and Zodiac Pool Systems have announced that their variable speed pumps have been Energy Star certified. Several other pumps have been certified or are close and will be posted on a website soon, according to Kent.
Now that there’s an Energy Star program in place for inground residential pool pumps, it is hoped that more utilities will begin offering rebates. The Energy Star designation spares them from having to develop their own guidelines: Instead, they only have to state that the products be certified to qualify.
The EPA periodically reviews Energy Star product categories to make sure that the baseline criteria still represent the top 25 percent of units for energy efficiency. The frequency of review depends on how quickly that particular product category changes. Televisions, for instance, are evaluated yearly because models come and go very fast. Porras expects pool pumps to be reviewed about every three years. If the products have become more efficient overall, the 3.8 energy factor requirement would likely be raised.
But the industry can’t rest easy now that a program is in place, says Jeff Farlow, program manager of energy initiatives for Pentair Aquatic Systems in Sanford, N.C. The EPA monitors Energy Star product categories to make sure they are performing as expected. Pumps are fairly unique in one respect: While many of the Energy Star products require merely that the homeowner plug it in, pumps must be correctly installed to achieve the maximum energy savings. For the program to stay in place, Farlow warns, the pumps must be put in properly. Energy Star designations have been revoked in the past for not performing to expectation.
“In order to get the savings with a pool pump, it needs to be installed so that it maximizes time on the low-flow operating point, which is not automatic,” Farlow says.
Variable speed pumps allow consumers to take advantage of the affinity law, which states that when a pump motor’s speed is reduced by half, it’s energy consumption goes down to one-eighth of the original amount.
Accomplishing this requires programming the units to run differently than in the past. Whereas traditionally, residential pool pumps often ran six hours a day to turn the water over once, variable-speed pumps must be programmed to push lower flows for longer periods of time, except when operating cleaners, spas and other features that require high flows. Additionally, these units need to be plumbed with larger pipe.
These requirements concern some experts, who believe more professionals need to be educated on proper installation and programming.
“The educational opportunity for the industry is to move on from trying to convince people that two-speed and variable-speed pumps are preferred and save energy, but to educate the trades about what you can do to the pool to allow these products to save more energy,” Fernstrom says. “That’s where the industry needs to go in the future.”
With the industry’s first Energy Star program in place, some professionals are looking forward to the next.
Currently, the EPA doesn’t have anything in the works, but officials would like to expand it to include aboveground and commercial pool pumps, as well as sump pumps.
Others say that, farther down the line, they’d like to see certifications for LED lights and heat pumps made specifically for pools and spas. Fernstrom believes pool cleaners also comprise an important category.
“There’s a pretty big difference between the energy used by different types of sweeps,” he says. “So there’s an opportunity for pool owners and sponsors of programs to recognize those differences.”
Many in the industry, especially service technicians, would like to see a program for replacement motors. This would be a less expensive alternative for consumers who want to save energy but don’t want to replace the whole pump, they say.
“If they were able to fit in these variable-speed motors and it had the Energy Star on them, which customers would recognize, probably the motors could be paid for in less than two years just from the energy savings,” says Michael Orr, executive director of the Foundation for Pool & Spa Industry Education in Sacramento, Calif. “And the price for the customer would be a bit less than having a whole new pump put in.”
Since the motor is the source of power, some believe, that’s where the savings really start. But it’s not that simple, say experts close to the Energy Star program.
For starters, the agency usually reserves Energy Star programs for whole products, not components such as replacement motors. In addition, it isn’t solely the motor that determines the efficiency of the pump, experts say. Wet ends also play a role. Some impellers, for instance, are more efficient than others, and that’s why energy factor was used as a determinant in assessing the eligibility of pool pumps.
At this point, no metric has been pinpointed to determine the efficiency of a motor, and there isn’t a collection of data to compare the different models on the market, as there is with pumps. So the EPA wouldn’t have a jumping-off point.
That may be changing soon, however. Last year, the Independent Pool & Spa Service Association conducted a study in the hopes of motivating utilities to begin offering rebates for multi-speed replacement motors. The results led the organization to estimate that the power used for a 15,000-gallon pool could decrease from 5.41- to 1.47 kilowatt hours when replacing a single-speed, 1-horsepower motor with a multispeed model operated at 40 gallons per minute.
In California, Title 20 is in the process of being revised, and some of this work may help bring about the idea of getting an Energy Star program in place for replacement motors.
“We’re going to be advocating for revising Title 20 in such a way that it includes testing, reporting and listing for pool pump motors, so that, when it’s done, it will help form a technical basis for getting motors included in these programs,” Fernstrom says.
Additionally, at least two motor manufacturers have reportedly agreed to begin testing their products, in the hopes of gathering more data and finding the best metric for quantify energy savings from a motor.
To qualify for the Energy Star designation, pumps must attain a 3.8 Energy Factor or higher when run at the speed setting to the right. During testing, readings are taken from a power meter and a flow rate meter at least once per second, with the values of at least a minute’s worth averaged out.
Photos courtesy apsp
source: gary fernstrom